1. Field of the Invention
The present invention relates generally to the unloading and packaging of brick and, more particularly, to an apparatus for forming a tyne layer in an automatic brick stacking system.
2. Description of the Prior Art
After brick are fired in a kiln, the kiln cars carry the bricks in open stacks to an unstacking area where they are placed on some type of conveyor which carries the bricks to the stacking and strapping section. The brick are normally unloaded from the kiln car in double layer courses and regrouped to form a number of rows and number of brick in each row for the final package. One standard size package in the United States is 5 brick long, 11 brick wide and 10 brick high.
The tyne layer is a layer of brick that usually includes a pair of openings where 2 rows, each 2 brick wide, are removed to allow an opening for the tynes of a fork lift truck to be received in order that the entire stack of brick may be moved after it is completed and strapped. The tyne layer is conventionally the third layer from the bottom of the completed brick stack. Additional courses of brick are then added to the tyne layer to complete the package.
Some automatic equipment has been developed to form these tyne courses, such as illustrated in U.S. Pat. Nos. 3,491,901 and 3,392,851. Both of the apparatus shown in these patents, however, are useful only in operating on single layer rows of brick and are not adapted for use with double layer courses. Using double layer courses, economics may be realized since twice as many brick may be handled during the same time interval.
U.S. Pat. No. 3,731,785, issued to Stewart, discloses an apparatus in which double layer courses of bricks, with the bricks in one layer atop the bricks in the other layer, are marshalled along a conveyor between a kiln car unstacking apparatus and a brick stacking and strapping apparatus. A pick-up head is lowered to a position overlying selected courses and a first set of gripper members are activated to grip the entire upper layer while a second set of grippers, independently operated from the first set, is activated to grip selected bricks in the lower layer, selected brick being those necessary to form the tyne openings. The pick-up head is then moved upward vertically and horizontally to a second position where the selected brick from the second level are deposited on a tyne brick table. The pick-up head is then moved to a third position where the upper level of brick is returned to its initial position atop the lower level in the same selected course.
U.S. Pat. No. 3,992,049, issued to Milholen et al., discloses an apparatus in which bricks are continuously received in double-layer courses. The courses are shifted one at a time onto a receiving plate whereupon a gripper apparatus is activated to grip the opposite sides of the course and retain the course as the receiving plate is removed from beneath the course. A platform is elevated to engage or cause the bricks already deposited thereon to engage the lower surface of the course being held by the gripper apparatus whereupon the gripper apparatus is deactivated. The elevator lowers and the receiving plate is returned to its initial position. During selected course transfers a tyne tray apparatus cooperates with the gripper apparatus to form tyne openings in selected layers.
However, as can be seen, in both of these solutions, the selected brick removed to form the tyne openings must be discarded or somehow reincorporated back into the stacks. This normally requires a full-time operator to oversee the operation of the machine.
Thus, there remains a need for a new and improved apparatus for forming tyne layers in an automatic brick stacking system which utilizes all the brick in a course of bricks being used to form a tyne layer which, at the same time, does not require an operator to oversee the operation of the apparatus.